N-acyl-pyrrolidinone derivatives

ABSTRACT

Novel pyrrolidinone derivatives of the formula ##STR1## wherein R 1 , R 2 , R 3 , R 4 , X and m have the meanings defined in the specification, useful as herbicides and nematicides.

This is a division of application Ser. No. 07/754,883, filed Sep. 4,1991, now U.S. Pat. No. 5,121,355.

The invention relates to novel N-acylpyrrolidine derivatives, to novelintermediates and processes for the preparation of the novelN-acylpyrrolidine derivatives, and to their use as herbicides andnematicides.

There were found novel N-acylpyrrolidine derivatives of the generalformula ##STR2## in which R₁, R₂ and R₃ independently of one anotherrepresent hydrogen, halogen, alkyl or aryl,

R₄ represents hydrogen, halogen, cyano, alkyl, aryl or ##STR3## R₅represents hydrogen, alkyl or aryl, R₆ represents alkyl or aryl,

X represents hydrogen, halogen or alkyl, and

m represents 1, 2 or 3.

All alkyl radicals can be straight-chain or branched. Furthermore, allalkyl and aryl radicals can optionally be substituted.

Furthermore, it has been found that the novel N-acylpyrrolidinederivatives of the formula (I) ##STR4## in which R₁, R₂, R₃, R₄, R₅, R₆,X and m have the abovementioned meaning area obtained when pyrrolidinederivatives of the formula ##STR5## in which R₁, R₂, R₃, R₄, R₅, X and mhave the abovementioned meaning

are reacted with acid halides of the formula ##STR6## in which R₆ hasthe abovementioned meaning and

Z represents halogen, in particular bromine or chlorine,

if appropriate in the presence of a diluent and if appropriate in thepresence of an acid-binding agent.

Finally, it has been found that the novel N-acylpyrrolidine derivativesof the formula (I) have a good action as nematicides as well as forcombating undesired plant growth.

Formula (I) provides a general definition of the novel N-acylpyrrolidinederivatives according to the invention. Preferred compounds of theformula (I) are those in which

R₁, R₂ and R₃ independently of one another represent hydrogen, fluorine,chlorine, bromine, optionally substituted C₁ -C₆ -alkyl or optionallysubstituted C₆ -C₁₀ -aryl,

R₄ represents hydrogen, fluorine, chlorine, bromine, cyano, optionallysubstituted C₁ -C₆ -alkyl, optionally substituted C₆ -C₁₀ -aryl or##STR7## R₅ represents hydrogen, optionally substituted C₁ -C₆ -alkyl oroptionally substituted C₆ -C₁₀ -aryl,

R₆ represents optionally substituted C₁ -C₆ -alkyl or optionallysubstituted C₆ -C₁₀ -aryl,

X represents hydrogen, fluorine, chlorine, bromine or optionallysubstituted C₁ -C₄ -alkyl, and

m represents 1, 2 or 3,

where the following are in each case suitable as alkyl substituents inthe definitions of R₁, R₂, R₃, R₄, R₅, R₆ and X: fluorine, chlorine,bromine, hydroxyl, methoxy or ethoxy, and the following are in each casesuitable as aryl substituents in the definitions of R₁, R₂, R₃, R₄, R₅and R₆ : fluorine, chlorine, bromine, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy.

Particularly preferred compounds of the formula (I) are those in which

R₁ represents hydrogen, fluorine, chlorine, bromine, methyl, ethyl,n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, t-butyl, phenyl ornaphthyl,

R₂ represents hydrogen, fluorine, chlorine, bromine, methyl, ethyl,phenyl or naphthyl,

R₃ represents hydrogen, fluorine, chlorine, bromine, methyl or ethyl,

R₄ represents hydrogen, fluorine, chlorine, bromine, cyano, methyl,ethyl, phenyl, methoxycarbonyl or ethoxycarbonyl,

R₅ represents methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl,s-butyl, t-butyl or phenyl,

R₆ represents methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl,s-butyl or t-butyl, or represents phenyl which is optionallymonosubstituted to trisubstituted by identical or different substituentsfrom the series comprising fluorine, chlorine, bromine, methyl, methoxy,hydroxyl, trifluoromethyl, trifluoromethoxy and trifluoromethylthio,

X represents hydrogen, chlorine, bromine, methyl or ethyl, and

m represents 1, 2 or 3.

Very particularly preferred compounds of the formula (I) are those inwhich

R₁ represents hydrogen, fluorine, chlorine or methyl,

R₂ represents hydrogen or methyl,

R₃ represents hydrogen,

R₄ represents hydrogen,

R₅ represents hydrogen, fluorine, chlorine or methyl,

R₆ represents methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl,s-butyl or t-butyl, or represents phenyl which is optionallymonosubstituted or disubstituted by identical or different substituentsfrom the series comprising fluorine, chlorine and trifluoromethyl, and

m represents 3.

If, for example, 2-trifluoromethyl-2-methyl-pyrrolidine and2,6-dichlorobenzoyl chloride are used as starting substances, the courseof the reaction of the process according to the invention may beillustrated by the following equation: ##STR8##

Formula (II) provides a general definition of the pyrrolidinederivatives to be used as starting substances in the process accordingto the invention for the preparation of compounds of the formula (I).

In formula (II), R₁, R₂, R₃, R₄, R₅, X and m preferably, or inparticular, have those meanings which have already been mentioned abovein connection with the description of the compounds of the formula (I)according to the invention as being preferred, or particularlypreferred, for R₁, R₂, R₃, R₄, R₅, X and m.

The pyrrolidine derivatives of the formula (II) are novel and equally asubject of the present invention. The compound2-trifluoromethylpyrrolidine is excluded (cf. Isv. Akad. Nauk SSSR, Ser.Khim., 1422 (1988)).

The novel pyrrolidine derivatives of the formula (II) are obtained by aprocess in which

a) nitroalkyl compounds of the formula (IV) ##STR9## in which R₁, R₂,R₃, R₄, X and m have the abovementioned meaning and

Y represents --COR₅ or --CN, where

R₅ has the abovementioned meaning,

are reduced intermediately to give the corresponding aminoalkylcompounds of the formula ##STR10## in which R₁, R₂, R₃, R₄, X, m and Yhave the abovementioned meaning,

and the compounds of the formula (V) are cyclised at temperaturesbetween 25° and 150° C., preferably between 40° and 90° C., preferablywithout intermediate isolation, and if appropriate in the presence of adiluent such as, for example, methanol or ethanol. Examples of reducingagents which can be used are all customary reducing agents such as, forexample, complex alkali metal hydrides such as lithium aluminiumhydride.

It is preferred to use hydrogen under a partial pressure of 5 to 150bar, preferably 40 to 80 bar, in the presence of suitable catalysts suchas, for example, Raney nickel, palladium/active carbon or copperchromite.

The product can be worked up, for example, by filtration, extraction ofthe pyrrolidine derivative, for example using ether, and subsequentdistillation.

Alternatively, the pyrrolidine derivative of the formula (II) can alsobe precipitated in hydrochloride form by adding aqueous hydrochloricacid after the filtration. The pyrrolidine derivative (II) can thenagain be set free from the hydrochloride by treatment with aqueousalkali metal hydroxide solution, and can be isolated by extraction, forexample using diethyl ether, and subsequent distillation.

The pyrrolidine derivatives of the formula (II) are obtained asracemates/diastereomer mixtures. A resolution or concentration can beeffected by known processes. (cf. DE-OS (German Offenlegungsschrift)3,739,784).

Alternatively, the novel pyrrolidine derivatives of the formula (II) canbe obtained when

b) pyrrolidinone derivatives of the formula (VI) ##STR11## in which R₁,R₂, R₃, R₄, X and m have the abovementioned meaning,

are hydrogenated under drastic conditions, for example with hydrogen ata pressure of 150-250 bar, preferably at 180-200 bar, in the presence ofa suitable catalyst such as, for example, Raney nickel or copperchromite, at temperatures between 150° and 280° C., preferably 180° and120° C., if appropriate in the presence of a diluent, such as, forexample, methanol or water.

Formula (VI) provides a general definition of the pyrrolidinonederivatives.

In Formula (VI), R₁, R₂, R₃, R₄, X and m preferably, or in particular,have those meanings which have already been mentioned above inconnection with the description of the compounds of the formula (I)according to the invention as being preferred, or particularlypreferred, for R₁, R₂, R₃, R₄, X and m.

The pyrrolidinone derivatives of the formula (VI) are also novel and asubject of the present invention.

The novel pyrrolidinone derivatives of the formula (VI) can be preparedby a process in which nitroalkyl compounds of the formula (VII)##STR12## in which R₁, R₂, R₃, R₄, X and m have the abovementionedmeaning and

Y₁ represents --COOR;

where

R₇ represents hydrogen or C₁ -C₆ -alkyl,

are reduced intermediately to give the corresponding aminoalkylcompounds of the formula (VIII) ##STR13## in which R₁, R₂, R₃, R₄, X, mand Y₁ have the abovementioned meaning,

and the compounds of the formula (VIII) are cyclised at temperaturesbetween 25° and 130° C., preferably 50° and 90° C., preferably withoutintermediate isolation, if appropriate in the presence of a diluent suchas, for example, alcohols, such as methanol, or ethers, such as diethylether, tetrahydrofuran or dioxane, or water.

Examples of suitable reducing agents are complex alkali metal hydridessuch as lithium aluminium hydride or hydrogen at a pressure of 5-150bar, preferably 60-90 bar, in the presence of suitable catalysts such asnoble metal catalysts of sub-group VIII on support materials such as,for example, barium sulphate, aluminium oxide or carbon, furthermoreRaney nickel, Raney cobalt. Palladium/active carbon is preferably used.

The mixture can be worked up, for example, by filtration, removal of thediluent and distillation or recrystallisation.

The pyrrolidinone derivatives of the formula (VI) are obtained in theform of racemates/diastereomer mixtures. They can be resolved orconcentrated by known processes (cf., for example, DE-OS (GermanOffenlegungsschrift) 3,739,784).

The nitroalkyl compounds of the formulae (IV) and (VIII) are knownand/or can be prepared analogously to known processes (cf., for example,DE-OS (German Offenlegungsschrift) 3,739,784; DE-OS (GermanOffenlegungsschrift) 3,808,276).

Formula (III) provides a general definition of the acid halidesfurthermore to be used as starting substances in the process accordingto the invention for the preparation of compounds of the formula (I).

In formula (III), R₆ preferably, or in particular, has that meaningwhich has already been mentioned above in connection with thedescription of the compounds of the formula (I) according to theinvention as being preferred, or particularly preferred, for R₆. Zrepresents halogen, in particular chlorine or bromine.

Acid halides of the formula (III) are generally known compounds oforganic chemistry.

Suitable diluents for carrying out the process according to theinvention are, preferably, all inert organic solvents. These include, inparticular, aliphatic and aromatic, optionally chlorinated hydrocarbonssuch as benzine, benzene, toluene, xylene, methylene chloride,chloroform, carbon tetrachloride, chlorobenzene and o-dichlorobenzene,ethers such as diethyl ether, diisopropyl ether, dioxane andtetrahydrofuran, ketones such as acetone, butanone, methyl isopropylketone and methyl isobutyl ketone, nitriles such as acetonitrile andpropionitrile, and the highly-polar solvents dimethylsulphoxide andhexamethylphosphoric triamide.

The process according to the invention is preferably carried out in thepresence of a suitable acid-binding agent. Suitable acid-binding agentsare all inorganic and organic bases which can customarily be used. Thefollowing are preferably used: alkali metal alcoholates such as sodiumtert-butylate or potassium tert-butylate, sodium tert-amylate orpotassium tert-amylate, alkali metal carbonates such as, for example,sodium carbonate, potassium carbonate and sodium hydrogen carbonate,furthermore lower tertiary alkylamines, cycloalkylamines orarylalkylamines such as, for example, triethylamine,N,N-dimethyl-benzylamine, furthermore pyridine, and also1,4-diazabicyclo[2.2.2]octane and 1,5-diazabicyclo-[4.3.0]non-5-ene.

When carrying out the process according to the invention, the reactiontemperatures can be varied within a substantial range. In general, theprocess is carried out at temperatures between -30° C. and +200° C.,preferably at temperatures between 0° C. and +110° C.

In general, the process according to the invention is carried out underatmospheric pressure. For carrying out the process according to theinvention, the starting substances to be used are generally employed inapproximately equimolar amounts. However, an excess of one or the othercomponent up to about 10% causes no problems.

When carrying out the process according to the invention, the reactionis preferably carried out using one of the abovementioned acid-bindingagents in one of the above-mentioned diluents. The reaction mixture isstirred for one hour at the temperature required. The reaction mixtureis worked up and the reaction products of the formula (I) according tothe invention are isolated in a generally customary fashion.

The active compounds of the formula (I) according to the invention havea powerful action against nematodes and can furthermore be employed inpractice for combating undesired plant growth. The active substances aresuitable for use as plant protection agents, in particular as herbicidesand nematicides.

The active compounds according to the invention can be used asdefoliants, desiccants, agents for destroying broad-leaved plants and,especially, as weed-killers. By weeds, in the broadest sense, there areto be understood all plants which grow in locations where they areundesired. Whether the substances according to the invention act astotal or selective herbicides depends essentially on the amount used.

The active compounds according to the invention can be used, forexample, in connection with the following plants.

Dicotyledon weeds of the genera: Sinapis, Lepidium, Galium, Stellaria,Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio,Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum,Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala,Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis,Papaver and Centaurea.

Dicotyledon cultures of the genera: Gossypium, Glycine, Beta, Daucus,Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana,Lycopersicon, Arachis, Brassica, Lactuca, Cucumis and Cucurbita.

Monocotyledon weeds of the genera: Echinochloa, Setaria, Panicum,Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus,Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis,Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea,Dactyloctenium, Agrostis, Alopecurus and Apera.

Monocotyledon cultures of the genera: Oryza, Zea, Triticum, Hordeum,Avena, Secale, Sorghum, Panicum, Saccharum, Ananas, Asparagus andAllium.

However, the use of the active compounds according to the invention isin no way restricted to these genera, but also extends in the samemanner to other plants.

The compounds are suitable, depending on the concentration, for thetotal combating of weeds, for example on industrial terrain and railtracks, and on paths and squares with or without tree plantings.Equally, the compounds can be employed for combating weeds in perennialcultures, for example afforestations, decorative tree plantings,orchards, vineyards, citrus groves, nut orchards, banana plantations,coffee plantations, tea plantations, rubber plantations, oil palmplantations, cocoa plantations, soft fruit plantings and hopfields, andfor the selective combating of weeds in annual cultures.

The active compounds according to the invention are furthermoreoutstandingly suitable for combating animal pests, preferably nematodes.

The phytoparasitic nematodes include Pratylenchus spp., Radopholussimilis, Ditylenchus dipsaci, Tylenchulus semipenetrans, Heteroderaspp., Meloidogyne spp., Aphelenchoides spp., Longidorus spp., Xiphinemaspp., Trichodorus spp., Globodera rostochiensis.

The active compounds can be converted into the customary formulations,such as solutions, emulsions, wettable powders, suspensions, powders,dusting agents, pastes, soluble powders, granules, suspension-emulsionconcentrates, natural and synthetic materials impregnated with activecompound, and very fine capsules in polymeric substances.

These formulations are produced in a known manner, for example by mixingthe active compounds with extenders, that is liquid solvents and/orsolid carriers, optionally with the use of surface-active agents, thatis emulsifying agents and/or dispersing agents and/or foam-formingagents.

In the case of the use of water as an extender, organic solvents can,for example, also be used as auxiliary solvents. As liquid solvents,there are suitable in the main: aromatics, such as xylene, toluene oralkylnaphthalenes, chlorinated aromatics and chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, forexample petroleum fractions, mineral and vegetable oils, alcohols, suchas butanol or glycol as well as their ethers and esters, ketones, suchas acetone, methyl ethyl ketone, methyl isobutyl ketone orcyclohexanone, strongly polar solvents, such as dimethylformamide anddimethyl sulphoxide, or such as water.

As solid carriers there are suitable:

for example ammonium salts and ground natural minerals, such as kaolins,clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceousearth, and ground synthetic minerals, such as highly disperse silica,alumina and silicates, as solid carriers for granules there aresuitable: for example crushed and fractionated natural rocks such ascalcite, marble, pumice, sepiolite and dolomite, as well as syntheticgranules of inorganic and organic meals, and granules of organicmaterial such as sawdust, coconut shells, maize cobs and tobacco stalks;as emulsifying and/or foam-forming agents there are suitable: forexample non-ionic and anionic emulsifiers, such as polyoxyethylene fattyacid esters, polyoxyethylene fatty alcohol ethers, for example alkylarylpolyglycol ethers, alkylsulphonates, alkyl sulphates, arylsulphonates aswell as albumen hydrolysis products; as dispersing agents there aresuitable: for example lignin-sulphite waste liquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latexes, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, as well as naturalphospholipids, such as cephalins and lecithins, and syntheticphospholipids, can be used in the formulations. Further additives can bemineral and vegetable oils.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs and metal phthalocyaninedyestuffs, and trace nutrients such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95 per cent byweight of active compound, preferably between 0.5 and 90%.

For combating weeds, the active compounds according to the invention, assuch or in the form of their formulations, can also be used as mixtureswith known herbicides, finished formulations or tank mixes beingpossible.

Mixtures with other known active compounds, such as fungicides,insecticides, acaricides, nematicides, bird repellants, plant nutrientsand agents which improve soil structure, are also possible.

The active compounds can be used as such, in the form of theirformulations or in the use forms prepared therefrom by further dilution,such as ready-to-use solutions, suspensions, emulsions, powders, pastesand granules. They are used in the customary manner, for example bywatering, spraying, atomizing or scattering.

The active compounds according to the invention can be applied eitherbefore or after emergence of the plants.

They can also be incorporated into the soil before sowing.

The amount of active compound used can vary within a substantial range.It depends essentially on the nature of the desired effect. In general,the amounts used are between 0.01 and 15 kg of active compound perhectare of soil surface, preferably between 0.05 and 10 kg per ha.

Preparation Examples Example 1 ##STR14##

A solution of 8.83 g (0.05 mol) of 2,6-difluorobenzoyl chloride in 10 mlof tetrahydrofuran (THF), to which 5.6 g (0.055 mol) of triethylaminehad been added, was added dropwise to a solution of 7.65 g (0.05 mol) of2-trifluoromethyl-2-methylpyrrolidine in 25 ml of tetrahydrofuran (THF).The reaction is exothermic, and slow dropwise addition prevented thetemperature from rising above +35° C. Stirring was continued for onehour at room temperature, and the mixture was then poured into 250 ml ofice-water and acidified using dilute hydrochloric acid, and theprecipitate obtained was filtered off with suction, washed thoroughlywith water and dried. 9.96 g (68% yield of theory) ofN-(2,6-difluorobenzoyl)-2-trifluoromethyl-2-methyl-pyrrolidine ofmelting point 119°-120° C. are obtained.

Example 2 ##STR15##

A solution of 6.03 g (0.05 mol) of 2,2-dimethylpropionyl chloride in 25ml of THF was added dropwise to a solution of 7.65 g (0.05 mol) of2-trifluoromethyl-2-methylpyrrolidine in 15 ml of THF, to which 5.6 g(0.055 mol) of triethylamine had been added. The course of the reactionis exothermic. The dropwise addition was effected slowly enough that thetemperature did not rise to above 35° C. Stirring was continued for onehour at room temperature, and the mixture was then poured into 200 ml ofice-water, the pH was adjusted to 4-5 using dilute hydrochloric acid,and the mixture was extracted twice using 60 ml portions ofdichloromethane. The combined organic phases were dried over magnesiumsulphate and filtered, and the solvent was stripped off under a waterpump vacuum. The oil which remained was chromatographed over a shortsilica gel column (mobile phase toluene/ethyl acetate 1:1). After themobile phase had been removed, 9.12 g (77% yield of theory) ofN-pivaloyl-2-trifluoromethyl-2-methylpyrrolidine are obtained as a paleyellow oil having a refractive index of n_(D) ²⁰ : 1,4615 (GC purity:97.7%).

Example 3 ##STR16##

1.6 g (0.01 mol) of 2-fluorobenzoyl chloride were dissolved in 100 ml ofabsolute tetrahydrofuran. A solution of 1.4 ml (0.01 mol) oftriethylamine and 1.67 g (0.01 mol) of2,3-dimethyl-2-trifluoromethyl-pyrrolidine, dissolved in 10 ml ofabsolute tetrahydrofuran, was slowly added dropwise at 0° C. When theaddition had ended, the batch was allowed to come to room temperature,and stirring was continued for one hour. For working up, 50 ml ofmethylene chloride were added, and the mixture was then washed insuccession with 2N hydrochloric acid, saturated NaHCO₃ solution andsaturated NaCl solution. To purify the crude product, the mixture waschromatographed (mobile phase mixture: ethyl acetate/cyclohexane 1:2).

2.5 g (86%) ofN-(2-fluorobenzoyl)-2,3-dimethyl-2-trifluoromethyl-pyrrolidine with thedata:

¹ H-NMR (CDCl₃, 200 MHz): 1.115 d, J=7 Hz (3H); 1.35-1.95 m (2H); 2.60 m(1H); 1.70 s (3H); 3.35 m (2H); 7.04-7.38 m (4H) are obtained.

The compounds of the general formula (I) which are listed in Table 1 canbe prepared analogously to the Preparation Examples and following thegeneral instructions for the process according to the invention##STR17##

                                      TABLE 1    __________________________________________________________________________    Example No.           R.sub.1              R.sub.2                 R.sub.3                   R.sub.4                     R.sub.5                        R.sub.6   CF.sub.m X.sub.3-m                                         Physical Data    __________________________________________________________________________    4      CH.sub.3              CH.sub.3                 H H H                                  CF.sub.3                                         M.p. 66-67° C.    5      CH.sub.3              H  H H CH.sub.3                         ##STR18##                                  CF.sub.3                                         M.p. 94-96° C.    6      CH.sub.3              H  H H CH.sub.3                         ##STR19##                                  CF.sub.3                                         M.p. 103-104° C.    7      CH.sub.3              H  H H H                         ##STR20##                                  CF.sub.3                                         Oil, IR: 2980; 1660; 1455 cm.sup.-1    8      H  H  H H CH.sub.3                         ##STR21##                                  CF.sub.3                                         Oil, IR: 2950; 1655; 1380 cm.sup.-1    9      H  H  H H CH.sub.3                         ##STR22##                                  CF.sub.3                                         M.p. 72-74° C.    10     H  H  H H H                         ##STR23##                                  CF.sub.3                                         Oil, IR: 2950; 1660; 1390 cm.sup.-1    11     CH.sub.3              H  H H H                         ##STR24##                                  CF.sub.3                                         M.p. 92-93° C.    12     CH.sub.3              H  H H CH.sub.3                         ##STR25##                                  CF.sub.3                                         M.P.92-94° C.    13     CH.sub.3              CH.sub.3                 H H H                         ##STR26##                                  CF.sub.3                                         M.p. 58-60° C.    14     H  H  H H CH.sub.3                         ##STR27##                                  CF.sub.3                                         Oil, IR: 2970; 1660; 1385    __________________________________________________________________________                                         cm.sup.-1

Preparation of the starting compounds

a) of the formula (II)

Example 15 ##STR28## Variant A

In a V4A stirred autoclave of volume 0.7 l, 100 g (0.5 mol) of4-(trifluoromethyl)-4-nitropentan-1-al were hydrogenated at 80° C. for 8hours in 300 ml of methanol on 10 g of Raney nickel. The hydrogenpartial pressure was 80 bar; 90% of the theoretic amount of hydrogen wastaken up. For working up, the catalyst was filtered off and rinsed witha little methanol. The methanolic solution was rendered acidic using 100ml of concentrated hydrochloric acid and concentrated to dryness underreduced pressure. The results were 59 g (0.34 mol) of2-trifluoromethyl-2-methyl-pyrrolidine hydrochloride (67% of theory).2-Trifluoromethyl-2-methyl-pyrrolidine (b.p.₁₀₁₃ : 115°-118° C.) wasobtained from the hydrochloride by adding an equimolar amount of sodiumhydroxide solution, extraction with diethyl ether, drying over sodiumsulphate followed by removal of the solvent by distillation over aVigreux column of 30 cm in length.

Example 16 ##STR29## Variant B

In a V4A stirred autoclave of volume 0.7 l, 98 g (0.5 mol) of4-(trifluoromethyl)-4-nitropentanecarbonitrile were hydrogenated for 8hours at 100° C. in 300 ml of methanol on 10 g of Raney nickel. Thehydrogen partial pressure was 70-80 bar, 85% of the theoretic amount ofhydrogen was taken up. For working up, the catalyst was filtered off andwashed with a little methanol. The further procedure was as in Example15. 57 g (0.3 mol) of 2-trifluoromethyl-2-methyl-pyrrolidinehydrochloride were obtained (60% of theory).

Example 17 ##STR30## Variant C

In a 0.3 l V4A stirred autoclave, 41.5 g (0.25 mol) of5-trifluoromethyl-5-methyl-pyrrolidin-2-one were hydrogenated for 16hours at 180°-190° C. in 100 ml of methanol on 5 g of copper chromite(CuCr₂ O₄). The hydrogen partial pressure was 220-240 bar; 80% of thetheoretic amount of hydrogen was taken up. Working-up was analogous toExample 15.

25 g (0.13 mol) of 2-trifluoromethyl-2-methyl-pyrrolidine hydrochloridewere obtained (53% of theory).

The compounds of the general formula (II) listed in Table 2 can beprepared analogously to Examples 15, 16 and 17 and following the generalinstructions ##STR31##

                                      TABLE 2    __________________________________________________________________________                                    Physical    Example No.           Variant                R.sub.1                   R.sub.2                      R.sub.3                        R.sub.4                          R.sub.5                             --CF.sub.M X.sub.3-m                                    Data    __________________________________________________________________________    18     A    H  H  H H CH.sub.3                             CF.sub.3                                    B.p..sub.1013 : 118-120° C.    19     A    CH.sub.3                   H  H H CH.sub.3                             CF.sub.3                                    B.p..sub.1013 : 125-126° C.    20     A    CH.sub.3                   CH.sub.3                      H H H  CF.sub.3                                    B.p..sub.1013 : 121-124° C.    21     A, C H  H  H H H  CF.sub.3                                    *)    __________________________________________________________________________     *) see Isv. Akad. Nauk SSSR, Ser. Khim, 1422 (1988)

b) of the formula (VI)

Example 22 ##STR32##

In a V4A stirred autoclave of volume 0.7 l, 108 g (0.50 mol) of methyl5,5,5-trifluoro-4-nitropentanecarboxylate were hydrogenated at 60° C.for 6 hours in 300 ml of methanol on 10 g of 5% palladium-on-carbon. Thehydrogen partial pressure was 60 bar, 95% of the theoretic amount ofhydrogen were taken up. For working up, the catalyst was filtered offand rinsed with a little methanol. The solvent was removed bydistillation under a water pump vacuum, first at 40° C. and then at 80°C. During this process, the residue began to solidify. For furtherpurification, a distillation under water pump vacuum was carried out.

57 g (0.37 mol) of 5-trifluoromethyl-pyrrolidin-2-one of boiling pointb.p.₁₄ : 122°-124° C. were obtained (74.5% of theory).

Example 23 ##STR33##

115 g (0.5 mol) of methyl 4-trifluoromethyl-4-nitropentanecarboxylatewere reacted and worked up analogously to Example 22.

After recrystallisation from ligroin, 72 g (0.43 mol) of5-trifluoromethyl-5-methyl-pyrrolidin-2-one of melting point 111°-112°C. were obtained (86% of theory).

Use Examples Example A-1

One part by weight of the compound obtained in Example 9 was mixed with4 parts by weight of acetone, 1 part by weight of alkylaryl polyglycolether was added as the emulsifier, and the mixture was diluted withwater. In this way, a preparation of an active compound was obtained.

This preparation was intimately mixed with soil which was heavilyinfested with Globodera rostochiensis (=test nematodes). Theconcentration of the active compound in the preparation is of virtuallyno importance, only the amount of the active compound per unit volume ofsoil is decisive. This amount was 20 ppm (=mg/l). The soil which hasbeen treated in this way was filled into pots, potatoes were planted,and the pots were kept in a greenhouse at 20° C.

After 6 weeks, the potato roots were examined for cysts. It was foundthat the preparation of the active compound had suppressed 95% of theinfestation in a comparison with controlled plants in soil which wasuntreated, but infested in the same manner.

Example A-2

One part by weight of the compound obtained in Example 14 was mixed with4 parts by weight of acetone 1 part by weight of alkylaryl polyglycolether was added as the emulsifier, and the mixture was diluted withwater. In this way, a preparation of an active compound was obtained.

This preparation was intimately mixed with soil which was heavilyinfested with Meloidogyne incognita (=test nematodes). The concentrationof the active compound in the preparation is of virtually no importance,only the amount of the active compound per unit volume of soil isdecisive. This amount was 20 ppm (=mg/l). The soil which has beentreated in this way was filled into pots, lettuce was sown, and the potswere kept in a greenhouse at 25° C.

After 4 weeks, the salad roots were examined for cysts. It was foundthat the preparation of the active compound had suppressed 95% of theinfestation in a comparison with controlled plants in soil which wasuntreated, but infested in the same manner.

What is claimed is:
 1. A pyrrolidinone derivative of the formula##STR34## in which R₁, R₂ and R₃ independently of one another representhydrogen, halogen, optionally substituted C₁ -C₆ -alkyl or optionallysubstituted C₆ -C₁₀ -alkyl,R₄ represents hydrogen, halogen, cyano,optionally substituted C₁ -C₆ -alkyl, optionally substituted C₆ -C₁₀-alkyl or ##STR35## X represents halogen, and m represents 1, 2, or3,the optional substituents on alkyl in the definitions of R₁, R₂, R₃and R₄ being selected from the group consisting of fluorine, chlorine,bromine, hydroxyl, methoxy and ethoxy, and the optional substituents onaryl in the definitions of R₁, R₂, R₃ and R₄ being selected from thegroup consisting of fluorine, chlorine, bromine, C₁ -C₄ -alkyl and C₁-C₄ -alkoxy.
 2. A pyrrolidinone derivative according to claim 1, inwhichR₁, R₂ and R₃ independently of one another represent hydrogen,fluorine, chlorine or bromine, R₄ represents hydrogen, fluorine,chlorine, bromine, cyano, or X represents fluorine or, chlorine, and mrepresents 1, 2 or
 3. 3. A pyrrolidinone derivative according to claim1, in whichR₁ represents hydrogen, fluorine, chlorine, bromine, methyl,ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, t-butyl, phenyl ornaphthyl, R₂ represents hydrogen, fluorine, chlorine, bromine, methyl,ethyl, phenyl or naphthyl, R₃ represents hydrogen, fluorine, chlorine,bromine, methyl or ethyl, R₄ represents hydrogen, fluorine, chlorine,bromine, cyano, methyl, ethyl, phenyl, methoxycarbonyl orethoxycarbonyl, m represents 3.